LEAP guidelines - End Allergies Together

Ready, Set, LEAP!
By Dr. Brian Schroer

Last week, the food allergy world was set aflutter by National Institute of Health’s (NIH) new guidelines for the early introduction of peanut to help in the prevention of peanut allergy development. This move is another step in the right direction to implement the findings of LEAP (Learning Early About Peanut) study that was released and heavily publicized two years ago. Media, however, often misconstrues the information with sensational headlines, which further illustrates the significant need for education among healthcare providers and parents. Many people have questions; there seems to be a lack of clear and concise answers. In this exclusive Q&A for End Allergies Together (EAT), Dr. Brian Schroer fills in the blankety-blanks on who, what, when, why and, perhaps most important, how. Below, in bold, are questions submitted by parents about how to interpret these new guidelines with Dr. Schroer’s responses immediately following…

Is there a lower chance that infants as young as four months would have anaphylaxis to peanuts if they are allergic versus when they are older? It has been reported to be rare. Is that because many 4-month- olds were not eating peanuts before?

I am sure some kids could have peanut allergy at this age, and they did find them in screening for the LEAP study. I agree it is not common because kids did not commonly eating peanut that early in life before these recommendations. Food allergy can and does start early. This is why it is important to intervene early and often.

I often see people say LEAP would not have helped their kids because of genetic predisposition. In the study, I read that there were kids who were already testing positive to peanut, but successfully consumed them throughout. What is your take on whether these guidelines can help, and are appropriate, for families with a history of allergies and atopic disease?

These guidelines are written precisely for kids who were predisposed by genetics to develop peanut allergy. They are mostly meant for children with severe eczema and/or another food allergy. These are both genetic conditions. Those are the children who were studied in the trial.

Along these lines, what is the role of oral food challenges in a clinical setting for babies/toddlers versus in-home introductions?

Basically the question is, “Who should do a challenge in the office and who should introduce peanuts at home?”

First, it would be impossible to introduce every high-risk food in every high-risk kid in the office. Put another way, it would be impossible to prevent every peanut, milk, egg, tree nut, fish, shrimp, etc. food allergy reaction from occurring at home. It may be “safer” to do it in the office, but mostly unnecessary. If this were our goal, then allergists would have infinite job security and make more money! It would be medicalizing normal – the vast majority of kids should eat new foods at home.

When would you consider skin testing or blood testing an infant before ingestion of peanut? When would you consider going straight to ingestion without testing first?

The amendment to the 2010 food allergy practice parameters lays out who should be tested before introduction and who is safe to eat peanut at home without previous testing. It is very clear. High-risk kids receive testing first. All others should eat the food at home.

Group 1 (high-risk): Skin test should be done (or blood test only if skin test is not available in a timely manner) in the kids at highest risk before eating peanut. The high-risk group is defined by kids with severe eczema or another food allergy. The guidelines say egg allergy, but I would do it for a kid with any existing anaphylaxis to food.

If testing is negative, then do the initial ingestion at home. In this high-risk group from the LEAP study, only 1/272 of the negative SPT kids reacted without need for epinephrine to treat the reaction. Remember – this is the highest risk group.

If testing is positive, depending on the level, the child should be offered a peanut food challenge in the office soon after the testing is done.

Group 2: For kids with mild eczema, which are kids who do not need topical medication therapy, then introduce peanut-containing foods at home by six months. Nobody knows the rate of reactions in these kids, but is likely very low.

Group 3: All other kids without eczema or other food allergies, even if there is a family history, should eat peanut at home when people feel comfortable. The EAT (Enquiring About Tolerance) NEJM study from 2016 also suggests that early introduction is safe and may prevent peanut allergy in this group of kids who do not have allergic problems.

Should other solids (i.e., vegetables) be introduced first? I had read that peanut should not be the first food.

Yes, have the child eat other foods before giving forms of peanut containing foods. Too many people could mistake normal “learning how to eat” issues for a reaction if peanut went first.

From what I read, 11% of the babies who showed sensitization to peanut and were given a small amount of peanut to eat had still developed a peanut allergy when they were retested five years later. Do you have any theories as to why early introduction of peanut did not prevent a peanut allergy for those kids? Why would it work for some, but not all?

What you are saying is that kids in the high-risk group whose skin testing was positive at a level of 4mm or less were reported to have an 11% rate of peanut allergy at the age of five years old when you look at the intention to treat protocol results.

HOWEVER, when you look at the study in detail, by the per protocol analysis, it is remarkable that ALL of the kids who “failed” (the 11%) had the allergic reaction during the initial food challenge. If you look at the kids in this group who passed the initial peanut food challenge, nobody became allergic over the next four-plus years. Therefore, it is possible – but rare – that kids who are able to tolerate the peanuts early will become allergic later.

Another way of thinking about these recommendations is to not think about it “working.” Think about the alternative of delayed introduction as “not working” by increasing risk to develop peanut allergy. LEAP-recommended early and often introduction is restoring normal (i.e., eat food such as peanut as an infant). Unnecessary avoidance increases risk.

How do you feel that the NIH guidelines should be applied in accordance to the WHO guidelines (infants should be exclusively breastfed until six months old)?

Many experts agree that the WHO guidelines recommending exclusive breastfeeding before six months need to change. They remind me of the previous AAP recommendations to avoid foods like peanut and egg until certain ages. Both those and the WHO recommendations are based on no good evidence. The LEAP and EAT studies would suggest that there is risk to these recommendations in high-risk kids.

Given that infants with eczema are at a higher risk for peanut allergy, do you consider “cradle cap” to be eczema?

Kids with cradle cap in the absence of other signs of eczema should not be considered to have the same risk as those with severe eczema.

Since an egg allergy is seen as a risk factor, do you recommend deliberately feeding eggs first? Or, potentially going straight to peanut?

The EAT study last year also adds to evidence that early introduction of high-risk foods such as eggs is likely better than delayed introduction at preventing egg allergy. However, that may be more risky in the high-risk group. There are not guideline recommendations about how to introduce egg. This is similar to the lack of recommendation about when to introduce peanut before these recommendations were released. We do not have evidence to answer the question.

This raises a larger point – what is so special about peanut? Nothing. It just happens that they were able to do an amazing randomized controlled to answer the question, “Is eating peanut earlier and often better than delaying introduction to prevent peanut allergy?”

That study may be done for egg. But what about tree nuts? I surmise that a similar study for tree nuts may be very hard to do. Why? To answer, I will ask you, “Would you be willing to sign your up your high-risk child for a randomized controlled trial of early and often tree nut ingestion versus avoidance for five years in order to see which group develops more tree nut allergy when you know the answer to peanut?” That is going to be a hard sell.

I would love to see those studies for egg, milk and tree nuts, but they will take a while.

The news stories are, by and large, overlooking advice on what to do if it appears your child is reacting. This exclusion seems to be the big objection from others dealing with food allergies – we are putting these infants at risk without properly preparing the parents. Are initial reactions unlikely to require medical attention? What should we be telling parents who are not familiar with food allergies?

Again, see my discussion about what is our goal. It would be impossible to prevent all reactions from occurring at home. In fact, currently, almost all patients have a reaction to a food, then see the allergist.

These guidelines only apply to advice on how to decrease the frequency of peanut allergy in high-risk kids. They have nothing to do with preparing parents for potential allergic reactions when kids eat all of the new foods they will eat throughout their lives. Most babies will have minor reactions and will not require epinephrine. I am sure that most parents reading this will say, “But our first reaction was severe!” Yes, that happens unfortunately. Each one of my patients who presents with a new food allergy comes after their reaction occurred at home. It would be impossible to prevent. I do agree that high-risk kids should talk to their doctors about how to recognize a reaction. But doing the peanut early and often will likely prevent many kids from having reactions at home because it will prevent them from developing peanut allergy in the first place.

Would breastfeeding factor into the decision for those with severe eczema and history of sibling with peanut allergy? Meaning, would the exposure to peanuts via breastfeeding or through broken skin be more likely to lead to sensitization and need to directly ingest peanut at four months old?

It seems clear that not eating the food, through breast milk only, is not enough to protect the high-risk kids from developing a peanut allergy. The LEAP study did not report the percentage of participants whose mothers were eating peanut and breastfeeding before starting the study. I suggest it may have been low since in England, there was a strong recommendation to not eat peanut while pregnant or breastfeeding leading up to the start of LEAP study recruitment, which began in 2008.

So, no, it should not deter or prevent kids from talking to their doctors to discuss how to introduce peanut.

Any tips for safely feeding a younger sibling foods to which an older sibling is allergic?

This is a difficult and common scenario. As the father of a 7-year-old with severe milk allergies and a 3.5-year-old who lives on milk and cheese, I empathize and sympathize with this situation. I think that being careful without being neurotic is the best way. There is no easy way around it.

But the wrong answer is to not give the younger kid the allergenic food because you want to protect the older kid. At least for peanut, this increases the risk the younger child will end up with the peanut allergy. One allergic kid is better than two.

Are there any plans to follow these kids longer term? I am curious if they will be at higher risk for developing a peanut allergy later in life?

The LEAP-ON (Persistance of Oral Tolerance to Peanut) study was published last year, which followed the study participants for one year after eating peanut as desired. The study showed that the kids remained tolerant. They are studying this group of kids long term. It has only been two years since the initial LEAP study was published in early 2015. Time will tell.

Dr. Brian Schroer is a pediatric allergist/immunology in Cleveland, Ohio and affiliated with Cleveland Clinic. These are his opinions and not the opinions of Cleveland Clinic.